Peritoneal Equilibration Test (PET)

What is a peritoneal equilibrium test (PET)?

People with kidney failure who are on peritoneal dialysis (PD), a type of dialysis involving cleansing of the blood without removing it from the body, will undergo a peritoneal equilibration test (PET) within a month or two after starting PD. The goal of the PET is to determine how well the peritoneal membrane, which lines the abdomen and helps filter waste and excess fluids from the body, is working.

How peritoneal equilibration test works and what it shows

During peritoneal dialysis a fluid consisting of sugar (dextrose), salt and other minerals dissolved in water is passed into the abdominal cavity by way of a catheter. The dextrose draws waste and fluids from the blood vessels in the peritoneum and also prevents waste from passing back through. The liquid mix of waste and fluid is then drained out of the abdomen. The entire filling and removal process is called an exchange.

A PET measures:

  • How much dextrose your body has absorbed from the fluid
  • How much urea and creatinine (waste products) have been absorbed into the fluid

These factors are an indication of how large or small the pores of your peritoneal membrane are and whether you’re a high, average or low “transporter,” which refers to how quickly or slowly your blood is cleansed during peritoneal dialysis. With this understanding your doctor can then determine how many exchanges you’ll need per day, what type of dialysis fluid to use and how long it should “dwell” or remain in your abdomen.